The spenopalatine ganglion (SPG) is involved in many intracranial processes, including vasodilatation, vasoconstriction, inflammation, and pain. Sphenopalatine ganglion (SPG) blockade is reported to be effective in some patients suffering from migraine or cluster headaches. The first reference to such techniques originates in 1917 (see, for example, Ref. 1). Various surgical procedures are now available, the most popular of which is percutaneous SPG radiofrequency rhizotomy, reported to relieve pain after surgery. In addition, gamma knife radiosurgery of the trigeminal nerve and endoscopic ganglion blockade are also being used for the same purpose. Though the control of an acute pain attack may be achieved with local application of anesthetic agents, repetitive SPG blockade has not generally achieved acceptance in neurological circles. Pharmacological blockade of the SPG is based on transnasal, transoral, transpalatine, and lateral approaches of administration of nerve blocking agents such as lidocaine (Refs. 1-3). For example, the transnasal application of topical anesthetic is a simple and common technique (Ref. 7); however, the diffusion of topical anesthetic to the ganglion is difficult to control, and such a blockade is not durable. Topical anesthesia to the nasal mucosa between the middle and inferior turbinates from nares to the nasopharynx, followed by a needle insertion in the same tract, brought a longer relief.
Thus, nasal administration of local anesthetic and pharmacological agents such as lidocaine or cocaine was found to be effective both in relieving acute pain and for the long term control of pain, but it is extremely complicated to control dosage during nasal delivery of these agents, while clinical response being unpredictable. Furthermore, some nasal preparations have significant adverse effects, some are not well absorbed and therefore do not work consistently, and others are challenging due to their complex delivery ways.
Headache is a very common symptom, causing immense suffering to the patients, and it is often associated with disability; migraines afflict 24 million people in the US alone (Ref. 6). Managing the problem is complex and often unsuccessful. About one third of the migraine patients do not respond to the available treatments today or cannot stand the side effects. Many of those who can accept the available treatments are handicapped by the side effects such as confusion and drowsiness. Eventual use of local aesthetics might be helpful, but due to the mentioned drawbacks of the available delivery means, a need for improved delivery system is urgently felt. It is therefore an object of the invention to provide an efficient system for long term delivery of therapeutic agents, so addressing said current technological and clinical unmet needs.
It was demonstrated that an efficient nerve block anesthesia can be achieved via the greater palatine canal, enabling dental and oral surgery without general anesthetic (Refs. 3-5). It is therefore another object of the invention to provide an efficient method for long term delivery of therapeutic agents, comprising releasing said agents via a palatine canal and especially via the greater palatine canal.
It is a still another object of the invention to provide a method for treating a cerebral neurovascular disorder, comprising placing near the spenopalatine ganglion (SPG) a solid dosage ensuring a long-acting release of a pharmaceutical ingredient capable of partially or fully block the SPG.
It is further an object of the invention to provide a solid dosage ensuring a long-acting release of a pharmaceutical ingredient near a dorsonal nerve structure, such as SPG.
It is a still further object of the invention to provide a solid dosage ensuring a long-acting release of a pharmaceutical ingredient capable of reducing the severity and incidence of cranial pain.
It is also a further object of the invention to provide a solid dosage for use in alleviating or healing headache, such as migraine, cluster headache, and tension headache.
Other objects and advantages of present invention will appear as description proceeds.